/*
 * Copyright (C) 2009 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect;

import static com.google.common.base.Preconditions.checkArgument;

import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;

/**
 * MapMaker emulation.
 *
 * @author Charles Fry
 */
public final class MapMaker
{
    private int initialCapacity = 16;

    public MapMaker()
    {
    }

    public MapMaker initialCapacity(int initialCapacity)
    {
        if (initialCapacity < 0)
        {
            throw new IllegalArgumentException();
        }
        this.initialCapacity = initialCapacity;
        return this;
    }

    public MapMaker concurrencyLevel(int concurrencyLevel)
    {
        checkArgument(
                concurrencyLevel >= 1, "concurrency level (%s) must be at least 1", concurrencyLevel);
        // GWT technically only supports concurrencyLevel == 1, but we silently
        // ignore other positive values.
        return this;
    }

    public <K, V> ConcurrentMap<K, V> makeMap()
    {
        return new ConcurrentHashMap<K, V>(initialCapacity);
    }
}
